From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759368AbYENAHU (ORCPT ); Tue, 13 May 2008 20:07:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753964AbYENAHG (ORCPT ); Tue, 13 May 2008 20:07:06 -0400 Received: from e5.ny.us.ibm.com ([32.97.182.145]:40165 "EHLO e5.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756773AbYENAHF (ORCPT ); Tue, 13 May 2008 20:07:05 -0400 Date: Tue, 13 May 2008 17:07:02 -0700 From: Gary Hade To: Yinghai Lu Cc: Jesse Barnes , Gary Hade , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Subject: Re: [PATCH] PCI: boot parameter to avoid expansion ROM memory allocation Message-ID: <20080514000702.GA12546@us.ibm.com> References: <20080512205746.GB7401@us.ibm.com> <20080513210054.GB28815@us.ibm.com> <86802c440805131411w1e0c661j93ba1a1854f314d6@mail.gmail.com> <200805131528.18252.jbarnes@virtuousgeek.org> <86802c440805131623v4ecd038djeab9bd9937717de6@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <86802c440805131623v4ecd038djeab9bd9937717de6@mail.gmail.com> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 13, 2008 at 04:23:55PM -0700, Yinghai Lu wrote: > On Tue, May 13, 2008 at 3:28 PM, Jesse Barnes wrote: > > > > There were some lkml/linux-pci visible discussions back in > > > > November-December of last year where I floated the idea > > > > of making PCI expansion ROM memory non-assignment the default: > > > > http://marc.info/?l=linux-kernel&m=119742188215024&w=2 > > > > http://marc.info/?l=linux-kernel&m=119689499508369&w=2 > > > > I did not hear any objections so I went ahead and submitted > > > > the change which entered mainline at 2.6.25-rc1 but it was > > > > sternly evicted last week because of a reported regression > > > > that it had caused: > > > > http://marc.info/?l=linux-kernel&m=121029093331908&w=2 > > > > Attachments to http://bugs.freedesktop.org/show_bug.cgi?id=15523 > > > > indicate that a 2.6.25-rc2 x86_64 kernel was being used. > > > > > > > > > can we use pci rom in 64 bit kernel? > > > > > > > > Sorry, not sure if I understand this question. I hope the > > > > above answers it. > > > > > > ok, i think the driver could reload fw in the option rom to reset the > > > controlller in pci card. > > > i don't think there is other usage for the option rom after OS loaded, > > > except option rom contain other run-time code... > > > > On graphics devices it's used for more than just POSTing (in fact POSTing is > > the least of its uses these days). The ROM often contains tables describing > > the specific hardware configuration of a given board, including output > > information, extra supported modes, etc. > > > > On other devices, it can be used to store default settings (this is common for > > SCSI cards iirc, though I'm not sure how much Linux drivers use this info). > > > > > > > so could disable them all, and use pci-quirks to enable that for the > > > device/driver need it. > > > > Since it's probably only big systems that really need the extra address space, > > I'd rather to the opposite: allocate ROM space by default and let a boot > > option avoid it. > > that boot option will get rid of that ROM BAR for all devices... > big system could use several graphical cards that need ROM BAR and > several cards that don't need ROM BAR. Correct, not a perfect solution but better than we have right now. Gary -- Gary Hade System x Enablement IBM Linux Technology Center 503-578-4503 IBM T/L: 775-4503 garyhade@us.ibm.com http://www.ibm.com/linux/ltc